A quality oil filter with the added convenience of hexagon screw/unscrew on the end of the filter. It makes filter changes a breeze, even on a Harley-Davidson where access to the filter is limited and a special oil filter spanner is needed. I have the spanner but it can stay in the toolbox as using it is just too fiddly. The K&N chrome is also top quality. I trust K&N with all filters for the Harley, the air filter is simply the best.